DoctorRofatnik, known to fans as “Doc,” looked almost mayoral in a tall white hat, a red tie and an American flag pin. A smirk was permanently plastered on his face as he roamed his domain on Roblox, ...

Roblox is one of the world’s biggest gaming platforms and it’s aimed squarely at kids. But critics say it hasn’t done enough to protect millions of users from child predators. “Over the years, people ...